You will need to use the TurboTax mobile app (if you don't already have it) to take a picture of your W-2. For step-by-step instructions, read the following TurboTax FAQ: How do I take a picture of my W-2 in TurboTax Onli ...
Once you have completed the steps, you can continue in the mobile app or sign into TurboTax Online where your information will now be uploaded.